The present disclosure relates to medical instruments. More particularly, the present disclosure relates to an apparatus and method for safely puncturing body tissue. More specifically, the disclosure relates to a surgical instrument having at least a single position indication system to positively indicate both when the puncturing portion is in a protective position and when it is in a non-protective position.
In various medical procedures, one or more surgical instruments may be used to puncture or penetrate body tissue. The body tissue may be penetrated in order to insert the instrument into a body cavity such as, for example, the abdominal cavity. Throughout the present application, the terms penetrating, piercing and puncturing and formatives thereof are used interchangeably. For example, an instrument known as a trocar that generally comprises a sharp pointed instrument, may be used to penetrate the abdominal wall to create an access hole therethrough into the abdominal cavity. In another example, an instrument known as a Veress needle or insufflation needle may be used. Veress-type needles use a hollow, blunt inner needle capable of fluid passage, and to carry insufflating gas into the abdominal cavity.
Needles to create pneumoperitoneum are used to insufflate the abdominal cavity to facilitate endoscopic examination and surgery. Laparoscopic surgical procedures require that a fluid or gas, such as carbon dioxide, be introduced into the abdominal cavity. This establishes pneumoperitoneum wherein the peritoneal cavity is sufficiently inflated for the insertion of trocars into the abdomen. The fluid may be introduced using a Veress or insufflation needle.
A Veress-type pneumoneedle has a spring-loaded, blunt tipped inner needle contained within a larger diameter piercing needle. The larger diameter needle is hollow and allows for passage of the blunt needle therein. In using such a needle, a user or user illustratively pushes the free end of the cannula against the body tissue, muscles and/or membranes forming the cavity wall of, for example, the abdomen of a patient.
Once the Veress-type needle penetrates the abdominal wall and enters the body cavity, the resistance against the end of the Veress-type needle is removed, so that the spring force causes the blunt needle or cannula to move forward, to extend beyond the sharp tip of the outer needle. This allows the needle to enter the body without puncture or laceration of any abdominal structures. In other words, the cannula retracts against the spring biasing, permitting the relatively sharper needle end to be forced, for example, through the abdominal wall into the abdominal cavity, whereafter the free end of the relatively blunt inner cannula pops out or extends from the relatively sharp needle via the spring biasing, thereby exposing the gas exit hole or aperture. This assumes that the needle is in an open area of the illustrative abdominal cavity or other body cavity and is not pushing against some other body tissue such as, for example, an internal organ or muscle, which would prevent the inner cannula from so popping out or moving to its extended position relative to the needle.
The physician can then connect a gas line to the valve or petcock and cause gas to enter into the Veress needle, pass through the cannula and exit out of the gas exit hole of the cannula into the abdominal cavity for insufflating the abdominal cavity. Alternatively, fluid can either be forced into or sucked from the abdominal cavity or other body cavity through use of the Veress needle.
If the needle goes beyond the peritoneum, the needle may perforate the stomach, small bowel, colon, bladder, or major vascular structures, the consequences of which can be fatal. The purpose of the spring-loaded safety tip of the Veress needle is to minimize the risk of visceral injury by covering the sharp tip once it has penetrated the peritoneum and reached a void. Generally, the surgeon relies on tactile senses to determine the proper placement of the needle by recognizing when the needle is inserted through the fascia and then through the peritoneum. However, this technique is often unreliable. It is sometimes difficult for a user, physician or surgeon to ascertain when the internal cavity wall has been breached by the Veress needle or trocar. Typically, the only indication is a reduction in the amount of resistance felt by the surgeon, with perhaps a mechanical vibration or sound caused by the forward movement of the spring biased needle or stylet once the internal cavity has been breached. Various devices have been developed to provide a more positive indication of when the cavity wall has been breached. These devices typically utilize visual or audible signals.
Some relevant examples of Veress needle and trocar instruments include Bauer et al., U.S. Pat. No. 4,379,458; Yoon, U.S. Pat. No. 4,535,773; Moll, U.S. Pat. No. 4,601,710; Moll et al., U.S. Pat. No. 4,654,030; Warring, U.S. Pat. No. 4,808,168; Adair, U.S. Pat. No. 4,869,717; Lander, U.S. Pat. No. 4,902,280; and Holmes, U.S. Pat. No. 4,931,042; Kulkashi et al., U.S. Pat. No. 5,098,388; Sewell, Jr., U.S. Pat. No. 5,290,276; Smith et al., U.S. Pat. No. 5,256,148; Scarfone et al., U.S. Pat. No. 5,669,883; Dennis, U.S. Pat. No. 5,853,392; Buncke et al., U.S. Pat. No. 6,245,091; and Clementine et al., U.S. Pat. No. 8,840,588; the disclosures of all of which are now expressly incorporated herein by reference.
After establishing pneumoperitoneum, the next step in laparoscopic surgery involves the insertion of a trocar into the abdominal cavity. It is through this first trocar that an endoscope is inserted into the abdominal cavity to provide the surgeon with a view of the rest of the operation. Trocars are similar to the Veress needle in that they are also equipped with a spring-loaded safety shield to avoid visceral injury. Trocars, like Veress needles, are inserted using a sudden thrust of the pointed tip into the abdomen. Therefore, as is true with the Veress needle, placement of the trocar is also vital, and the reliance of the surgeon on mere tactile senses for proper placement can be fatal.